Pneumatic hammer.



No. 788,875. PATENTED MAY 2, 1905.

J. BGHE'.

PNEUMATIG HAMMER.

APPLIOATION FILED MAY 13, 1903.

2 SHEETS-SHEET 1.

PATBNTED MAY 2, 1905.

J. BGHB'.'

PNEUMATIG HAMMER.

APPLICATION FILED MAY 13. 1903.

2 SHEETS-SHEET 2.

Patented May 2, 1905.

ENIGE.

JEAN BEeHE, or neKEswAeEN, eEaMANY.

PNEUMATIIC HAMMER..

SPECIFICATION forming part of Letters Patent No. 788,876, dated May 2, 1905.

Application led May 13, 1903. Serial No. 156,940.

To rtl/Z 1f/7mm ISI; 'may concern:

Beit known that I, JEAN BioHii,.a subject of the King' of Prussia, German Emperor, and a resident of Hiickeswagen, in the Province of the Rhine, German Empire, have invented certain new and useful Improvements in Pneumatic Hammers, of which the following is an exact specification.

My invention relates to improvements in pneumatic hammers, and more especially to such hammers in which two cylinders are provided, one of which cylinders forms the working cylinder propel', the other one being' provided with the striking-block piston.

In order to make my invention more clear, I refer to the accompanying' drawings, in which- Figure 1 is a vertical section ci? a pneumatic hammer constructed according' to my invention. Fig'. 2 is a vertical section of the operating parts of the same in another position. Fig. 3 is partly a front view and partly a vertical section of the hammer at a right angle to the section shown in Figs. 1 and 2. Fig'. i is a part oi' the section shown in Fig. E2, the regulating-valve standing in another position. Fig. 5 is a vertical section of the parts shown in Fig. It, the section being taken at a right angle to the preceding` one. Fig. 6 shows a modified construction of the working cylinder, and Fig. 7 shows this construction in another position of the piston.

As will be seen from the drawings, the striking-block of the hammer forms a cylin-` der a.. In" the cylinder a a iixed plunger bis situated. At its upper end the cylinderw is provided with an annular iiangc c, so that the cylinder has the outer shape oi a diiiierential piston. The iiange c is fitted into the lixed cylinder L. The lower cylindrical part oi the cylinder a is guided in a socket d, fixed in the cylinder J. By this arrangement three airspaces c, f, and g are created. The space e is situated in the hollow striking-block cylinder and the spaces f and g are situated in the cylinder /vthat is to say, the space g is situated above and the space f below the ring c. The working' piston l, situated in the cylinder 1. is also provided with a flange-shaped ring' 2.'. The lower cylindrical part of the Working' piston is guided in a socket fm., fixed in the cylinder v. By this construction two spaces of different cubical contents are formed-71. e., a space o above the piston and a space i2. below the piston. The space 0 is connected, by means of a channel (j, with the interior e oiI the striking-block. a is a small channel connecting the channel l] with the valve vi. The lower space a in the cylinder is connectechby means of the channel p, with the space j' in the cylinder 7) underneath the ring e, iixed to the stiikingblocl'c. is a channel connecting the valve /v with the space f/ above the ring c. The end oi the channel t is situated in a certain distance underneath the upper end of the cylinder so that after the striking-block having passed the end of the channel t an air-cushion is Jformed in the space As may be seen from Figs. 3 and 5, a second channel 'w leads l'rom the valve fu into the space y, which channel w ends also underneath the upper end of the cylinder, so that in case the channel fw isopened-that is to say, stands in connection with the atmosphereman air-eush ion is formed in the space g. The channel w can he connected with the atmosphere by means of an angular bore uw' of the valve o. rlhc channel fw is closed by means oi' a iiap or a backiiow-valve w, which iiap or valve allows the air to leave the space g, but not to enter into the same.

To the working piston Z a plunger-shaped part fr is fixed, which passes through a cylindrical opening ot' the cylinder-cover. The part r is provided atits upper and its lower end with ribs fr', so as to connect the interior of the cylinder with the outside when the part fr is in its highest or lowest position. The plunger-shaped part r is so Vformed that in case the working' piston is situated in its highest position, Fig'. l, air can pass around the lower ribbed part ot' the part fr, thereby effecting a compensation of the air-pressure in the space u, and that in case the working' piston is situated in its lowest position, Fig. 2, also a compensation ol the air-pressure in the space o takes place by the part r being in its lowest position. The lower partZ oi the working' piston is provided with openings a, which allow the entrance oit' airinto the space a in IOO case the working piston is in its highest position.

The pistonb is provided with tighteningrings s for tightening the striking-block. The arrangement of the tightening-rings at the piston 7) is very advantageous, as in case these rings are fixed to the striking-block piston these rings will very easily be damaged and wear out in consequence of the continuous shocks.

The effect of the above-described hammer is as follows: If the working piston goes downward from the position shown in Fig. l, a compressing of the air in the space n takes place. This air compression is transmitted through the channel p to the space f. In the space o above the piston a rarefying of the air takes place. rIhe rarefaction of the air is transmitted by the channel q to the space e within the striking-block. By the effect of the air compression and rarefaction the strikingblock is lifted. If the movement of the working piston is reversed, an air compression takes place in the space 0 and the rarefaction of the air takes place in the space f. The compression and rarefaction are transmitted again through the channels p and q to the spaces f and e. The compression in the space e will push the striking-block downward, and the effect of this compression will be augmented by the rarefaction of the air in the space f in case atmospheric pressure prevails in the space g.

In hammers with two separate cylindersthat is to say, with a working cylinder and a striking-block cylinder-it is necessary that the effective spaces in the working cylinder be larger than the corresponding spaces in the striking-block cylinder. If this were not the case, it would not be possible to attain a quick movement of the air in the striking-block cylinder. Consequently a quick lifting and pushing down of the -striking-block would not take place. In consequence hereof the space 0 must be considerably larger than the space e. If the working piston moves downward and the striking-block upward, a certain rarefaction of the air must be present in the space 0 and naturally also in the space e connected to the same. Now in order to attain that the working piston as soon as the movement of the same is reversed begins to operate the striking-block the rarefaction of the air must cease instantly, as otherwise the working piston would have to pass at first a deadway in order to do away with the rarefaction of the air by diminishing the cubical contents of the space 0. In order to attain this purpose, the plunger-shaped part r is provided. It will be seen from Fig. 2 that in case the working piston arrives in the lower dead-point the space ois connected with the atmosphere by the bore in the cylinder-cover. It is, furthermore, very important to attain that in the upper dead-point of the working piston atmospheric pressure prevails in the space o, for it will be clear that the rising working piston has effected in the space e during the downward movement of the striking-block a certain air compression, especially in consideration of the cubical contents of the space 0 being larger than the cubical contents of the space e. This air compression must be done away with in order to avoid the working piston having to pass a deadway. The compensation of the air-pressure takes place in the upper dead-point by the plunger-shaped part lr by the lower part of the same allowing the circulation of the air through the bore of the cylinder-cover, as may be seen from Fig. 1. During the working of the striking-block the valve o is in the position shown in Figs. l, 3. The space e is then connected to the space 0 and the space f to the space n. The space g in the cylinder b is connected by the channel to the atmosphere. By the rarefaction of the air in the space c and the compression of the air in the space f the striking-block is thrown upward until it passes the opening of the channel t and compresses the air in the space g. The air-cushion thus formed then serves as a buffer for the striking-block. If it is desired to stop the operation of the striking-block, the val ve o is brought into the position shown in Figs. 4 and 5. In this position of the valve o the channel tis closed, the channel u, however, which stands in connection with the channel q between the spaces e and o, is connected with the atmosphere. At the same time the channel zo is brought in connection with the angular bore w in the valve o. If the striking-block is lifted in the moment in which the channel t is closed, the striking-block will remain in its position by the rarefaction of the air in the space g, which arises in consequence of no air entering into the space g on account of the channel w, Figs. 3 and 4, being closed by the valve @02. If the striking-block would begin to sink in consequence of the valve not being perfectly tight, it will always be brought back again into its position, as in each stroke of the working piston airis pressed into the space f. rI`he striking-block must consequently remain in its raised position.

In the modification shown in Figs. 6 and 7 the plunger-shaped part 1" is not fixed to the working piston, but to the cover of the working cylinder k. rIhe cover of the cylinder is perfectly closed; but the hollow piston is provided with a bore for the part r. The effect of this modification is the same as described above, as the interior of the piston Z stands in connection with the atmosphere.

Having thus fully described the nature of this invention, what I desire to secure by Letters Patent of the United States is- 1. In pneumatic hammers, the combination of a working cylinder it', piston l, and a striking-block cylinder b' with a striking-block IOO IIO

IIS

consisting of a cylinder a, an annular flange c provided at the upper edge of the cylinder a, said annular lange being fitted into the striking-block cylinder 7)', a fixed plunger fitted into the cylinder' t and rigidly xed to the striking-block cylinder W, channels for guiding the air from the Working Cylinder to the striking-block cylinder and from the strikingblool; cylinder to the outer atmosphere, a valve for controlling the latter ehannehsubstantially as described and for the purpose set forth.

2. In pneumatic hammers, the combination of a Working cylinder 7n having an opening in one end, and a striking-block cylinder with a striking-block consisting of a cylinder a, an annular [iange c provided at the upper edge of the cylinder ci, said annular flange being Vfitted into the striking-block cylinder a OTTO KNIG, J. A. RlTTERSHAUs. 

